49 



out the British Isles. This was to have been expected, and calls 

 for no particular comment. It occurs in both sexes, apparently 

 with equal frequency, and has been found in persons of all ages 

 from the second year onwards (Matthews and Smith, Miss 

 Nutt). 



TUthough indigenous cases of E. coli infection were doubtless 

 known to workers in this country before the war, the first re- 

 corded in the literature appear to be two described by Smith and 

 Matthews (1917). Since then many others have been found by 

 the same workers and others. From the records it appears pro- 

 bable that the true incidence of infection with this organism in 

 the British Isles is high. Of the persons already examined, 

 probably between one-third and one-half were infected — taking 

 them in the aggregate. Some differences in distribution appear 

 in the various records, but for various reasons, already considered, 

 it is doubtful how far these are real. Campbell (p. 31) at 

 Bristol, and Miss Natt (p. 33) at Leeds, found the organism 

 commoner in adults than in children : but at Sheffield Miss Nutt 

 (p. 35) found the incidence in the two classes approximately 

 equal. Matthews and Smith (1919, p. 364) give the following 

 figures— based on one examination per case — for three classes of 

 persons examined by them : 



Civilian Army 



Children. Adults. Recruits. 



Percent, infected with £. coi! ... 11-1 ... 6-7 ... 18-2 



In a group of 207 asylum patients they found no less than 

 45-9 per cent, infected — as a result of only one examination per 

 case. This indicates a very high rate of infection in this group. 

 (See Matthews and Smith (1919 a), p. 91.) High figures were also 

 obtained for Welsh miners and some other groups. To judge 

 from most of the larger series, and those in which more than one 

 examination per case was made — these series being freer from 

 errors due to small sampling and deficient examination — it 

 appears probable that 50 per cent, is a conservative estimate of 

 the true incidence of infection with E. coli in the general popu- 

 lation of the British Isles. At present there is no conclusive 

 evidence indicating a localized distribution, except that derived 

 from lunatics in asylums — to which reference has just been 

 made. 



(3) Endolimax nana. — This small non-pathogenic amoeba ap- 

 pears to be common in Britain. The first British cases of infection 

 were found by Matthews and Smith— reported by Yorke (1918) 

 —and by Miss'D. L. Mackinnon (1918). The latter found three 

 out of thirty-four soldiers, who ' had never been out of England ', 

 infected with this organism. Since then Matthews and Smith 

 and all the workers under the War Office Dysentery Committee 

 have found further infections in other classes of cases. 



The percentages recorded in most series are low — the highest 

 being 12'1 per cent, found in asylum patients by Matthews and 

 Smith (1919 a). The patients were examined only once apiece : 



